Wireless communications networks are commonplace today as a wide variety of appliances or portable wireless devices, such as audio and video media players and personal digital assistants, are being developed to provide users with content via wireless communications channels. A typical portable wireless device includes a processor for executing specific software and performing required tasks, memory for storing programs and data, a display for conveying information to a user, a keypad or other type of input device to allow a user to input data, and a wireless interface for communicating over a wireless communications channel to other devices in the network. Because a portable wireless device is typically battery powered, the power consumption of the components in the device is ideally minimized to extend the life of the batteries.
While all components in a portable wireless device consume power, the wireless interface is in many instances the component that consumes the largest portion of the overall power. As a result, lowering the power consumption of the wireless interface will significantly lower the overall power consumption of the portable wireless device. A variety of different approaches have been utilized to lower the power consumption of the wireless interface. These approaches generally involve turning off the wireless interface based upon the information being communicated over the wireless communications channel. For example, one approach is to temporarily turn off the operation of the interface whenever a receive buffer in the portable wireless device is full. The rationale of this approach is that since the portable device cannot receive and store any more incoming message packets being communicated over the wireless communications channel, the interface is temporarily placed in a sleep mode to conserve power until the device can once again receive and store more incoming packets. A performance penalty is experienced with this approach, however, due to the increased time required to communicate the required message packets to the device. This increased time is caused by the periods of time during which the interface is placed in the sleep mode and unable to receive and store any packets being communicated.
Another approach is to determine whether message packets to be communicated over the channel are directed to a particular portable device. When they are not, the wireless interface is placed in the sleep mode to save power. This approach may not, however, result in much power savings in networks where broadcast message packets are transmitted by a device in the network. A broadcast message is a message that is intended to be received and processed by all portable wireless devices proximate the transmitting device. Broadcast messages can significantly reduce the opportunities for a given portable wireless device to place its wireless interface into the sleep mode, reducing the power savings that may be realized using this approach.
There is a need for lowering the power consumption of portable wireless devices without adversely affecting the performance of the communications channel used to communicate with the device.